Harvey AI vs. CoCounsel: Which Legal AI Platform Is Right for Your Firm?

Two platforms dominate the conversation when large law firms evaluate enterprise legal AI: Harvey AI and CoCounsel (formerly Casetext). Both are backed by serious investment, used at Am Law 200 firms, and claim to handle the full spectrum of legal work — research, drafting, contract review, and more.

But they are meaningfully different products, built on different philosophies, and better suited to different types of firms and workflows. Here is what we found after evaluating both platforms across six dimensions.

What Each Platform Does

Harvey AI

Harvey is built on a custom fine-tuned version of GPT-4 optimized for legal tasks. It functions as a general-purpose legal assistant that can draft documents, analyze contracts, conduct research, and assist with due diligence. Harvey has deep integrations with major document management systems and is designed to operate across entire practice groups rather than as an individual attorney tool.

CoCounsel

CoCounsel (now part of Thomson Reuters after the Casetext acquisition) is built around a suite of discrete legal AI skills: contract review, legal research, deposition preparation, document summarization, and more. It integrates directly with Westlaw, giving it a significant advantage in legal research depth. CoCounsel positions itself as a paralegal-grade AI assistant that handles specific, well-defined tasks with high reliability.

Research Quality

CoCounsel has a meaningful edge here due to its Westlaw integration. It can search the full Westlaw database, retrieve on-point cases, and synthesize holdings with strong citation accuracy. For litigation firms, this alone may be decisive.

Harvey performs well on general legal research but lacks the same depth of primary source access. It excels at synthesizing complex legal concepts and drafting research memos, but attorneys should independently verify case citations.

Edge: CoCounsel for primary source research accuracy.

Contract Review

Harvey was purpose-built for transactional work and shows it. Its contract review capabilities are deeply integrated into M&A and financing workflows, with the ability to review against negotiating playbooks, flag non-standard clauses, and produce redlines. For corporate and finance practices, Harvey is the stronger choice.

CoCounsel offers contract review as one of its skills but is less optimized for the back-and-forth of transactional negotiation. It performs better as a first-pass review tool than as an end-to-end contract workflow platform.

Edge: Harvey for transactional contract work.

Security and Compliance

Both platforms offer SOC 2 Type II certification and contractual guarantees against training on client data. Both support data processing agreements for GDPR compliance.

Harvey offers additional enterprise controls including SSO, role-based access controls, and audit logging — making it more suitable for firms with complex IT governance requirements.

CoCounsel benefits from Thomson Reuters' established enterprise security infrastructure, which may be reassuring for firms already in the TR ecosystem.

Edge: Roughly equal, with Harvey having more granular enterprise controls.

Pricing

Both platforms are enterprise-priced and require direct negotiation. Harvey is generally positioned at a higher price point, reflecting its enterprise focus. CoCounsel offers per-seat licensing that can be more accessible for mid-size firms.

Neither publishes list pricing publicly. Expect significant variation based on firm size, usage volume, and negotiating leverage.

Which Should You Choose?

If you are…	Consider…
A corporate / M&A practice	Harvey AI
A litigation-heavy firm	CoCounsel
Already using Westlaw	CoCounsel
Running complex due diligence	Harvey AI
A mid-size firm watching costs	CoCounsel
An Am Law firm needing firm-wide deployment	Harvey AI

The best approach for most firms evaluating enterprise AI is to pilot both platforms on real work before committing. Both Harvey and CoCounsel offer enterprise pilots — use that window to test on your actual matters with your actual attorneys.